The third son of Luigi Scalabrini and Colomba Trombetta, he had three brothers and as many sisters.

From 1851 to 1857 he attended classical studies at the High School Lyceum ‘A. Volta’ in Como. In the years 1859-1860 at the ‘Gallio’ College he held the office of Prefect, in the company of Luigi Guanella, three years his junior, now a saint.

After high school he began studying philosophy at the Seminary of S. Abbondio (of which he was rector from 1867) and theology at the Major Seminary in Como. He was ordained deacon on September 20^th, 1862 and became priest on May 30th 1863 at the age of 24.

A teacher in the aforementioned seminary, he held the position of vice-rector and then rector there from 1868-1870. To these years dates his great friendship, which was to have an important place in the life and work of both with Bishop Geremia Bonomelli. The latter, then provost in Lovere, had been invited to preach a course of spiritual exercises in the Como Seminary.

On May 12th 1870, Scalabrini was appointed parish priest prior of San Bartolomeo in Como, where he developed his pastoral activity by elaborating and subsequently publishing The Catholic Catechism and the Piccolo catechismo per gli asili d’infanzia (1875).

He was elected bishop of Piacenza by Pope Pius IX at the age of 36, consecrated in Rome on January 30^th, 1876; on February 13th of the same year, he took possession of the diocese.

For the nomination “… the joy of the people of Piacenza was great, not so much for having a bishop so soon, as for having Monsignor Scalabrini as bishop, whose fame, especially after the publication of the Lectures on the Vatican Council, had already surpassed the borders of the diocese of S. Abondio”.

Here is how Scalabrini himself, twenty-eight years later, narrates the news of his episcopal appointment to an Editor of the Turin newspaper ‘La Stampa’:” I was then Prior of St. Bartholomew’s in Como, and one morning I was in my church, when I saw an unknown canon enter (Canon D. Davide Celli of the Cathedral), who approached me with great acts of obsequiousness. I asked him if he wanted to say Mass, but he replied that he had already celebrated it and that he had come to pay his respects to his bishop, that is to say, to me, who had been appointed bishop of Piacenza. I fell from the clouds and did not want to believe the announcement, indeed I begged him to come and refresh himself in my house, but to leave immediately, because I did not want that surprising rumour to spread. He did so, but on the same day I received a letter from Rome with the official news of the appointment’.

He died on 1 June 1905 in Piacenza. In that year, the marble monument placed in the right transept of

 the cathedral was built for him, by Alessandro Monti for the architectural part and Annibale Monti for the figurative one.  In the lower part, a marble ark has a bas-relief on the front depicting the bishop’s journey to America, among migrants. At the ends within niches are two female figures; in the upper part the plinth above the roof supports the bust-portrait of the holy bishop. As a backdrop to the monument, an architectural element defined by small columns support the entablature with a triangular tympanum in the centre of which the prelate’s coat of arms stands out.

On November 9th 1997 Pope John Paul II proclaimed the Servant of God Bishop John Baptist Scalabrini blessed, and on October 9th 2022 Pope Francis proclaimed him saint.